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package cz.muni.fi.pb138.webrep.metadata.servlets;

import cz.muni.fi.pb138.webrep.UploadArtifactServlet;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.tomcat.util.http.fileupload.IOUtils;

/**
 *
 * @author Max
 */
@WebServlet(name = "DownloadXMLSerlvet", urlPatterns = {"/download/xml"})
public class DownloadXMLSerlvet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        if(request.getParameter("artifact") != null && request.getParameter("version") != null) {
            File file = new File(request.getServletContext().getRealPath("") + File.separator
                    + UploadArtifactServlet.UPLOAD_DIR + File.separator
                    + request.getParameter("artifact") + File.separator
                    + request.getParameter("version")+".xml");
            //System.out.println(file.getAbsolutePath());
            if(!file.exists()) {
                response.sendError(HttpServletResponse.SC_NOT_FOUND, "Soubor neexistuje"+ file.getCanonicalPath());
                return;
            }
            // code inspired by http://stackoverflow.com/a/8485963
            response.addHeader("Content-Type:","application/octet-stream");
            response.addHeader("Content-Disposition", 
                    "attachment; filename=\"web.xml\"");
            response.addHeader("Content-Transfer-Encoding","binary");
            response.addHeader("Content-Length", Long.toString(file.length()));
            
            try(
                    ServletOutputStream out = response.getOutputStream();
                    BufferedInputStream in = new BufferedInputStream(new FileInputStream(file));
                ) {
                IOUtils.copy(in, out);
            }
        }
        else response.sendError(HttpServletResponse.SC_NOT_FOUND, "Nebyly obdrženy nezbytné paramtery");
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}
